By Team NSHM | Apr 2, 2015

Preventable Blindness: Uncorrected Refractive Error

Refractive errors (myopia, hypermetropia, astigmatism, presbyopia) result in an unfocused image falling on the retina. Uncorrected refractive errors, which affect persons of all ages and ethnic groups, are the main cause of vision impairment. They may result in lost education and employment opportunities, lower productivity and impaired quality of life..

Uncorrected refractive errors are a major cause of blindness and low vision: it is estimated that 8 million people are blind and 145 million have low vision because of lack of adequate refractive correction.

Refractive error as a cause of blindness  in any population suggests that eye care services in general in that population are inadequate since treatment of refractive error is perhaps the simplest and most effective form of eye care. Refractive error would become the second largest cause of treatable blindness after cataract if blindness.

Uncorrected refractive errors can hamper performance at school/college, reduce employability and productivity, and generally impair quality of life. The correction of refractive errors with appropriate spectacles is among the most cost-effective interventions in eye health care.

Visual impairment from uncorrected refractive errors can have immediate and long-term consequences in children and adults, such as lost educational and employment opportunities, lost economic gain for individuals, families and societies, and impaired quality of life.

Refractive error can be detected through routine examination of patients who present to clinics, or through vision screening of the population at large.

Most refractive errors are easily treatable by appropriate refractive correction. However, high refractive error in childhood may lead to amblyopia, resulting in permanent vision loss if it is not corrected during early childhood. Refractive correction can be by spectacles, contact lenses, or refractive surgery. Spectacles are the most commonly used form of refractive correction since they are the most inexpensive and the simplest of the three options.

Following actions to be taken:

  • Screening of children for refractive errors should be conducted at community level and integrated into school health programmes, accompanied by education and awareness campaigns to ensure that the corrections are used and cultural barriers to compliance are addressed and removed.
  • As the cost of refractive corrections is still high compared with the personal and family resources in many regions, corrections must be accessible and affordable for people of all ages.
  • Eye-care personnel should be trained in refraction techniques. Training and information programmes should also be designed for teachers and school health-care workers.
  • Reliable and affordable equipment for refractive assessments should be developed.
  • Refraction services need to be integrated with eye-care systems and included as a part of cataract surgery services.
  • Impairment from uncorrected refractive errors, provision of refractive services and outcomes of the provisions should be monitored at national level to identify communities in need and evaluate the most cost-effective interventions.

Provision of spectacles is currently a challenge in many developing countries because of issues related to availability and affordability. There are often inequities in the availability of spectacles between urban and rural areas.

Blindness due to refractive error is a substantial public health problem in many parts of the world. Its presence implies inadequate eye care services in the population concerned since treatment of refractive error is probably the simplest and most effective of eye care interventions.

Source-   Dept. of Optometry, NSHM Knowledge Campus

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